when I was in highschool (Humanistisches Gymnasium) gym about 12 years old - a lot of my classmates had nicknames, which were often abbreviations from their second names: so 'Heuberger' became 'Heue (hoie)', 'Wolkerdorfer' changed to 'Wello', 'Dornderer' to 'Donde' etc. - After we learned in so called 'Heimatkunde' (history of the own town & surroundings) and heard that the founder of a nearby small village "Regelsbach" was a guy called 'Regilo' we called since then my then good friend 'Walter Regelsberger' 'Regilo' -
For long time I escaped a nickname, because my Name 'Heimo' was short enough (also my second name) & 'Heimo' (spelled high-maw) is a very seldom name I was proud of. - But then in about 3rd year of highschool, having Latin in the 3rd year too, we had in our lessons a lot of old litte historical fables & stories & then in one lessen there was also this "Ecce homo" meaning 'Behold the man' used by Pontius Pilate about Jesus.
So some of my classmates startet calling me 'Homo' instead of Heimo. - I didn't like that at all, because a) I liked my name like it was, b) a got also aware, that 'homo' (meaning equal in greek) was used as abbreviation for homosexual -
You should deeply avoid getting such a nickname if you're not gay or are gay & don't want to show it. -
So when they started calling me homo I simply didn't react in the slightest to that name. They had to call me by my real name to make me respond. & so they gave up pretty soon & I had avoided the stigma of that nickname.
I remember some years that my younger brother Wilfried - we used to call him 'Willi' which he later didn't like that much anymore. - So he wanted to invent his own nickname & tried to persuade us & others to use this new nick 'Gigi' - I can't remember that anyone ever called him Gigi. - Usually nicknames are given by others, whether you like it or not & only few (including me) seem to be able to escape a group-given nickname.